Differential driving mechanism



June 28, 1938.. o. HEUMADER I DIFFERENTIAL DRIVING MECHANISM Filed July 16, 1957 2 Sheets-Sheet l 2 June 28', 1938.

O. HEUMADER DIFFERENTIAL DRIVING MECHANISM FiledJuly 16, 1937 2 Sheets-Sheet 2 (lttorneg Patented June 28, 1938 Uhli'l'hfi STATES PATENT QFFIQE 14 Claims.

My invention relates to improvements in differential driving mechanisms, such as are employed in driving two opposite wheels of a car.

One of the objects of my invention is the pro- ;5 vision of novel differential driving mechanism of the kind described by which driving power will be applied to both driving axles to an extent and in a manner such that should one wheel become mired or otherwise loses traction, and the 1 other wheel is on a surface of sufficient traction, the latter will be rotated so as to propel the car.

A further object of my invention is the provision of novel means by which driving power will be applied to both driving axles whether or not 15 one wheel has little or no traction effect, which means, however, will permit the outer wheel in making a turn to revolve faster than the inner wheel.

Still another object of my invention is the pro- 20 vision of a novel differential driving mechanism of the kind described which is relatively simple, is inexpensive to make and install in cars already in use, which is strong, durable, not likely to get out of order, which can be readily and quickly 25 substituted for differential mechanisms now in use, and which is efficient in its operation.

The novel features of my invention are hereinafter fully described and claimed.

In the accompanying drawings, which illustrate 39 my invention,

Fig. 1 is a central horizontal sectional View, some parts being broken away and some shown in plan, of the preferred embodiment of my improved diiferential driving mechanism and parts 35 connected therewith.

Fig. 2 is .a section on the line 22 of Fig. 1, reduced.

Fig. 3 is a view similar to Fig. 1, showing a modification of my improved differential driving 40 mechanism.

Fig. 4 is a view similar to Fig. 1, showing another modification of my improved differential driving mechanism.

Fig. 5 is a central horizontal sectional view of some of the parts showing in Fig. 4, parts being in plan, and parts broken away, showing the reciprocative member and the intermediate gear with whichit engages in a position different from 50 that shown in Fig. 4.

.Fig. 6 is an end elevation of the intermediate gear with which the reciprocative member has engagement.

Fig. '7 is an enlarged end view of the recip- 55 rocative member shown engaged with one of the intermediate gears, the latter being shown in section and partly broken away.

Fig. 8 is a reduced section on the line 8-8 of Fig. 4, the housing being partly broken away.

Similar characters of reference designate sim- ,5 ilar parts in the different views.

Referring to Figs. 1 and 2, l designates the differential housing which is substantially of the usual construction adapted to contain oil. 2 is the usual drive shaft to which is affixed the usual 10 drive shaft pinion 3 which meshes with the usual ring gear 4, the latter being revoluble on the axis of the usual axles 5 and 6.

In my improved construction, shown in Fig. 1, the axles 5 and 6 are respectively splined in the 1 5 outer ends of two axially alined axle driving members I and 8, which outer ends are rotatably mounted in the end walls of the housing I.

The adjacent ends of the axle driving members 'l and 8 are respectively provided with axial cylindrical recesses 9 and Ill.

Reciprocative in the recesses 9 and I0, and snugly fitted therein, is a cylindrical horizontal member H provided with a peripheral abutment comprising a projecting pin 12. The member H forms with the recesses 9 and Ill two closed chambers l3 and M which are connected with each other by by-pass means of less cross sectional area than that of the member H. In

the drawings such by-pass means comprises a passage l5 extending longitudinally through the member 1!.

The chambers l3 and I4 and the passage or by-pass means l5 are filled with fluid, preferably lubricating oil such as is contained in the housing l. The function of the fluid in the chambers l3 and I4 and the passage I5 is to resist the reciprocation of the reciprocative member I l, and the amount of such resistance is dependent upon the cross sectional area of the passage I5, 40 the larger the diameter of such passage, the less will be the resistance ofiered by the fluid to the reciprocation of the member I I.

The foregoing description applies not alone to the form shown in Fig. 1, but it also applies 4,5 to the form shown in Fig. 3, and that shown in Fig. 4, so that like characters of reference have been applied to the corresponding parts in the different figures.

In each form of my invention, shown in Figs. 1, 3, and 4, means are provided which connect the reciprocative member with the axle driving members I and 8 by which rotation of one of said driving members will rotate the reciprocative member II .and through it the other axle driv- 5 5 ing member, and by which, when either axle driving member, I or 8, rotates faster than the other, the reciprocative member will be reciprocated, or moved longitudinally, in the recesses 9 and I0, and will, thereby, impede the rotation of the faster rotating driving member and will aid rotation of the slower rotating driving member, to an amount dependent upon the resistance ofiered by the fluid in the chambers I3 and I4 and passage I5.

The principal differences in structure between the three forms of my invention shown in Figs. 1, 3, and 4 reside in the different structural adaptations, which they respectively embody, of the just described means which connect the reciprocative member II with the axle driving members I and 8.

In the structural adaptation shown in Fig. 1, and in that shown in Fig. 2, the abutment pin I2 has traveling guiding engagement with an annular guide provided in the recess IIl consisting, as shown, of an annular groove I6 which is oblique to the axis of the axle driving member 8, and by means of which reciprocation, or endwise movement, of the member II is effected when either axle driving member rotates faster than the other. In both forms shown in Figs. 1 and 3, the member II is rotative in the driving member 3, and in both forms, the member II is held from rotation in the driving member I, by a key N mounted in the periphery of the member I I and slidably fitted in a longitudinal groove II in the member I in its recess 9.

In the form shown in Fig. 1, the axle driving member I is provided at its inner end with an annular peripheral flange I8 which is concen-- trio with and fastened by bolts I9 to the usual ring gear 1. The flange I8 is also fastened by bolts 20 to one end of a sleeve 2I in which the driving member 8 is rotatively fitted. The other end of the sleeve 2I bears against the adjacent end wall of the casing I. The inner end of the member 8 is provided with an annular peripheral flange 22 disposed in an annular groove 23 in the sleeve 2i. The latter serves as a bearing for the member 8 and to hold the members 'I and 8 from shifting endwise to the right.

In the structural adaptation shown in Fig. 3, ring gear 4 has bolted to it by bolts 24 the usual spider 25 in which the driving members I and 3 are rotative and upon which are supported oppositely disposed differential intermediate gear wheels 26 and 2B, which are rotatable and mesh each with two side gears 21 and 28 which, as shown, are integral with and rotate respectively with the driving members I and 8.

In the form shown in Fig. 1, when the ring gear 4 is rotated, and the car is moving straight ahead, with the tWo driving carrying wheels traveling with like traction effect, the ring gear l will rotate the driving member I, upon which the member II revolving therewith, will through the pin I2 revolve the driving member 8 at the same speed as the driving member I. If a turn, say a left turn, is made, the right Wheel and the driving member 8 will be caused to rotate faster than the left wheel and the driving member I. This will cause the pin I2 to travel in the annular guiding obliquely disposed groove I6, thus, due to the resistance of the fluid in the chambers I3 and I 4, causing the reciprocative member II to reciprocate, at a speed permitted by the fluid as it passes from one chamber to the of the driving member 8 and aiding the rotation the member II of the driving member I, but not sufliciently to cause the member 1 to rotate as rapidly as the member 8.

The contrary action will take place when a turn is made to the right. And, if one wheel is in soft mud with no or little traction, the wheel on good traction surface will be caused to revolve and move the car ahead, but it will not rotate as fast as the mired wheel.

In the form shown in Fig. 3, the driving action corresponds to the usual drive which employs a similar arrangement of pinion or diiferential gears carried by a spider and engaging with the gears on the axle driving members, excepting that if one wheel becomes mired and has no traction effect, and the other wheel has traction effect, the same driving action will be given the wheel having the good traction, as has just been described with reference to the form shown in Fig. 1, due to the same connection between the reciprocative member II and the axle driving members I and 8, through the pin I2 in the groove It, and the reciprocative splined connection between the member II and the driving member I.

In the form shown in Fig. 4, the same construction is provided as in the form shown in Fig. 3, excepting that, the member II is revoluble in both recesses 3 and iII, as well as reciprocative therein, and excepting that the oblique guiding groove I6 of the other two forms is omitted, and instead, the pin I2 is disposed in a recess 2!? disposed eccentrically in the end of the intermediate gear 25 next to the member I I.

When the axle driving members I and 8 are rotating at like speed, the intermediate gears 26 and 26' will not turn with respect to the gears 21 and 28, and the member II will not move endwise, but will revolve with the members I and 8 alike. If one wheel is mired and loses traction, and the other is on good traction surface, the pin I2 in the recess 23 will hold back on gear 26, thus causing the latter to rotate the wheel having good traction eifect, but at a speed slower than that of the mired wheel, an amount dependent upon the fluid resistance to the reciprocation of the member I I. When reciprocating, will oscillate circumferentially, but will resist turning in its axis of the gear 26, thereby aiding rotation of the wheel having good traction, while impeding the rotation of the mired wheel.

For keeping the chambers I3 and I4 and the passage I filled with fluid, similar means are provided in each form of my invention, shown in Figs. 1, 3 and 4. The specific means for eifecting this function, is shown in Figs. 1, 2, 4, and 8.

At the left end of the chamber I3, as shown in Figs. 1 and l, is provided a fluid inlet 30 in which is mounted a check valve 3i which opens toward the chamber I3. The inlet 3|] communicates with a transverse passage 32 extending transversely through the axle driving member I. The ends of the passage 32 communicate with an annular groove 33 in a sleeve 34 fitted on the driving member I.

A radial passage 35 in the driving member I communicates with the annular groove 33, and has fitted in it the inner end of a pipe 36, the other end of which is fitted in a hole 31 communicating with a passage 38 communicating with the outer end of a cylinder chamber 39 provided in a cylinder 43 fastened by bolts II to the inner side of the left end of the housing I.

An oil inlet 42 is provided at the outer end of the cylinder chamber 39, and'has fitted in it one end of a curved pipe 43, the other end of which is disposed in the housingI, adjacent to the bottom thereof. An inwardly openingcheck valve 44 is disposed across the oil inlet 42. An outwardly opening disk check valve 45 normally closes the outer end of the passage 38 which is disposed in a lateral tubular projection 46 on the cylinder 40. The outer end of the tubular projection 46 is threaded and has -fitted on it a screw cap 41 provided with lateral'openings '48. A coil spring 49 in the cap 41 bears at one end against the cap and at its other end it bears against the disk valve 45 and holds the latter seated.

'Reciprocative radially in the cylinder chamber 39 is a pump piston 50 attached to the outer end of a piston rod 5I, which is reciprocative in the inner end of the cylinder 48. The inner end of the piston rod'5I, outside the cylinder 48 has a head 52 against which bears one end of a coil spring 53, the other end of which bears on the cylinder 40.

For forcing the piston rod 5! and piston 50 outwardly radially, there is fastened on the driving member 1 a cam 54.

When the driving member 1 rotates, the cam 54 forces the piston 5| outwardly against the pressure of the coil spring 53, and thus moves the piston 50 outwardly, whereby oil in the cylinder chamber 39 is forced through the passage 38, pipe 36, annular groove 33, passage 32, and checkvalve 3| into the chamber I3, thus keeping this chamber, the chamber I4 and the passage I5 'full of oil.

I When a pressure in the passage 38 is suflicient to overcome the pressure of the coil spring 49, thedisk check valve 45 will open outwardly, permitting the excess oil which is pumped into the cylinder chamber 39 'to pass back into the housing I, through the passage 38, cap 41 and its lateral openings 48. By adjustment of the screw cap 41, the tension of the coil spring "49 may be adjusted, so as to vary'the pressure of the oil in the chambers I3, I4 and passage I5. The by-pass passage I5, by permitting the oil to pass backand 'forth'between the chambers I3 and I4, enables the pressures in the twochambers to equalize,-when the member I I is not moving endwise, andv the axle driving members are rotating at the same speed.

The diameter-of the passage I5 determines 'the maximum excess speed of rotation'that either axle driving member, 1 or 8, can attain relatively to the other. The larger the diameter of' the passage I5, the faster excess speed either driving member will have in making turns. The diameter provided is such as will best suit the shortest turn that can be made by the particular car. I

in the form shown in Fig. 3, the oil pumping mechanism is not included in the figure, but it corresponds to that already described with references to Figs. 1 and 4.

Other modifications of my invention, within the scope of the appended claims, may be made without departing from the spirit of my invention.

What I claim is:- Y V 1. In a differential mechanism of the kind described, the combination with two rotary axially alined axle driving members having 'in their adjacent ends respectively two axial recesses, of a revoluble member reciprocative longitudinally in said recesses and forming therewith two closed chambers, lay-pass fluid conductive means connecting said chambers and of less cross sectional area than that of said reciprocative member, fluid in said chambers and said Icy-pass means which resists reciprocation of said reciprocative member, and means connecting said reciprocative member with said axle driving members by which the rotation of one driving member will rotate the reciprocative member and therethrough the other driving member, and by which, when either axle driving member rotates faster than the-other, will reciprocate said reciprocative member and will, thereby, impede the rotation of the faster rotating driving member and aid the rotation of the slower rotating driving member to an amount depending upon the resistance 'ofiered by said fluid to the reciprocation of said reciprocating member.

2. In a differential mechanism of the kind described, the combination with two rotary axially alined axledriv'ing members having in their adjacent ends respectively two axial recesses, of a revoluble member reciprocative longitudinally in said recesses and forming therewith two closed chambers and having extending longitudinally therethrough a passage communicating with said chambers, fluid filling said chambers and said passage and which resists reciprocation of said reciprocative member, and means connecting said reciprocative member with said axle driving members by which the rotation of one driving member will rotate the reciprocative member and therethrough the other driving member, and by which, when either driving member rotates faster than the other, will reciprocate said reciprocative member, impede the rotation of the faster rotating member and aid rotation of the slower rotating member.

3. In a differential mechanism of the kind described, the combination with two rotary axially alined axle driving members having in their adjacent ends respectively two axial recesses, of a revoluble :member reciprocative longitudinally 'in said recesses and forming therewith two closed chambersand having a peripheralabutment, bypass fluid conducting means connecting said chambers and of less cross sectional area than that of said reciprocative member, fluid in said chambers :and said by-pass means which resists reciprocation of said reciprocative member, and means cooperating with said abutment in connecting said reciprocative member with said axle driving members by which the rotation of one driving member will rotate said reciprocative member and therethrough the other driving member, and by which, when either axle driving member rotates faster than the other, will reciprocate said reciprocative member, impede the rotation of the faster rotating member and aid rotation of the slower rotating member.

4. In :a differential mechanism of the kind described, the combination with two rotary axially alined axle driving members having in their adjacent ends respectively two axial recesses, of a revoluble member reciprocative longitudinally in said recesses and forming therewith two closed chambers, and having extending longitudinally there'through a passage-communicating with said chambers, and having a peripheral abutment, fluid fillingsaidchambers and said passage which resists reciprocation of said reciprocative member, and means cooperating with said abutment in connecting said reciprocative member with saidaxle driving members by which the rotation of one driving member will rotate said reciprocative member and therethrough the other driving member, and by which, when either axle driving member rotates faster than the other, will reciprocate said reciprocative member, impede the rotation of the faster rotating member and aid rotation of the slower rotating member.

"5. In a differential mechanism of the kind described, the combination with two rotary axially alined axle driving members having in their adjacent ends respectively two axial recesses, of a revoluble member reciprocative longitudinally in said recesses and forming therewith two closed chambers and having a peripheral abutment, and rotatable in one of said driving members, the latter having in its recess an annnlar guide oblique to the axis of said driving member and with which said abutment has traveling engagement by which said reciprocative member is reciprocated, means holding said reciprocative member from rotation in the other driving member, bypass fluid conducting means connecting said chambers and of less cross sectional area than that of said reciprocative member, and fluid filling said chambers and said by-pass means which resists reciprocation of said reciprocative member.

6. Ina difierential mechanism of the kind described, the combination with two rotary axially alined axle driving members having in their adjacent ends respectively two axial recesses, of a revoluble member reciprocative longitudinally in said recesses and forming therewith two closed chambers and having a peripheral abutment, and having through it a longitudinal passage communicating with said chambers, and rotatable in one of said driving members, the latter having in its recess an annular guide oblique to the axis of said driving member and with which said abutment has traveling engagement by which said reciprocative member is reciprocated, means holding said reciprocative member from rotation in the other driving member, and fluid filling said chambers and said passage and which resists reciprocation of said reciprocative member.

'7. In a differential mechanism of the kind described, the combination with two rotary axially alined axle driving members having in their adjacent ends respectively two axial recesses, of a revoluble member reciprocative longitudinally in said recesses and forming therewith two closed chambers and having a peripheral abutment, and rotatable in one of said driving members, the latter having in its recess an annular guiding groove oblique to the axis of said driving member and in which said abutment is disposed and is adapted for travel by which said reciprocative member is reciprocated, means holding said reciprocative member from rotation in the other driving member, by-pass fluid conducting means connecting said chamber and of less cross sectional area than that of said reciprocative member, and fluid filling said chambers and said bypass means and which resists reciprocation of said reciprocative member.

8. In a differential mechanism of the kind described, the combination with two rotary axially alined axle driving members having in their adjacent ends respectively two axial recesses, of a revoluble member reciprocative longitudinally in said recesses and forming therewith two closed chambers and having a peripheral abutment, and having lengthwise through it a passage communicating with said chambers, and rotatable in one of said driving members, the latter having in its recess an annular guiding groove oblique to the axis of the driving member and in which said abutment is disposed and adapted for travel by which said reciprocative member is reciprocated, means holding said reciprocative member from rotation in the other driving member, and fluid filling said chamber and said passage and which resists reciprocation of said reciprocative member.

9, In a differential mechanism of the kind described, the combination with two rotary axially alined axle driving members having in their adjacent ends respectively two axial recesses, of a revoluble member reciprocative longitudinally in said recesses and forming therewith two closed chambers, and having a peripheral abutment, and having through it a passage communicating with said chambers, and rotatable in one of said driving' members, the latter having in its recess an annular guide oblique to the axis of the driving member and with which said abutment has traveling guiding engagement by which said reciprocative member is reciprocated, means holding said reciprocative member from rotating in the other driving member, fluid filling said chambers and said passage and which resists reciprocation of said reciprocative member, and engine driven means for driving one of said axle driving members.

10. In a differential mechanism of the kind described, the combination with two rotary axia1ly alined axle driving members having in their adjacent ends respectively two axial recesses, of a revoluble member reciprocative longitudinally in said recesses and forming therewith two closed chambers, and having a peripheral abutment, and having through it a passage communicating with said chambers, and rotatable in one of said driving members, the latter having in its recess an annular groove oblique to the axis of the driving member and in which said abutment is guided and adapted for travel by which said reciprocative member is reciprocated, means holding said reciprocative member from rotating in the other driving member, fluid filling said chambers and said passage and which resists reciprocation of said reciprocative member, and engine driven means for driving one of said axle driving members.

11. In a difierential mechanism of the kind described, the combination with two rotary axially alined axle driving members having in their adjacent ends respectively two axial recesses, of a revoluble member reciprocative in said recesses longitudinally and forming therewith two closed chambers, and having a peripheral abutment, and. rotatable in one of said driving members, the latter having in its recess an annular guide oblique to the axis of said driving member and with which said abutment has traveling guiding engagement by which said reciprocative member is reciprocated, means holding said reciprocative member from rotating in the other driving member, by-pass fluid conducting means connecting said chambers and of less cross sectional area than that of said reciprocative member, fluid filling said chambers and said by-pass means which resists reciprocation of said reciprocative member, two gears on and respectively rotative with said driving members, an engine driven member rotative around the axis of said driving members, supporting means rotative with said engine driven member, and an intermediate gear meshing with said two gears and rotative on and revoluble with said supporting means.

12. In a differential mechanism of the kind described, the combination with two rotary axially alined axle driving members having in their adjacent ends respectively two axial recesses, of a revoluble member rotatable and longitudinally reciprocative in said recesses and forming therewith two closed chambers, and having a peripheral abutment, by-pass fluid conducting means connecting said chambers and of less cross sectional area than that of said reciprocative member, fluid filling said chambers and said by-pass means which resists reciprocation of said reciprocative member, two gears on and respectively rotative with said axle driving members, an engine driven member rotative around the axis of said driving members, supporting means rotative with said engine driven member, and an intermediate gear meshing with said two gears and rotative on and revoluble with said supporting means, and provided with an eccentric recess in which said abutment is disposed and is engaged with said intermediate gear and by which, on rotation of the latter said reciprocative member will be reciprocated and axially oscillated.

13. In a differential mechanism of the kind described, the combination with two rotary axially alined axle driving members having in their adjacent ends respectively two axial recesses, of a revoluble member reciprocative longitudinally in said recesses and forming therewith two closed chambers, by-pass conducting means connecting said chambers and of less cross sectional area than that of said reciprocative member, fluid filling said chambers and said by pass means and which resists reciprocation of said reciprocative member, means connecting said reciprocative member with said axle driving members by which the rotation of one of said driving members will rotate said reciprocative member and therethrough the other driving member, and by which, when either axle driving member rotates faster than the other, will reciprocate said reciprocative member and will, thereby, impede the rotation of the faster rotating driving member and aid the rotation of the slower driving member, and means for supplying one of said chambers with fluid.

14. In a differential mechanism of the kind described, the combination with two rotary axially alined axle driving members having in their adjacent ends respectively two axial recesses, of a revoluble member reciprocative longitudinally in said recesses and forming therewith two closed chambers, and having a peripheral abutment, and having through it a passage connecting said two chambers, and rotatable in one of said driving members, the latter having in its recess an annular guide oblique to the axis of the driving member and with which said abutment has traveling guiding engagement by which said reciprocative member is reciprocated, means holding said reciprocative member from rotation in the other driving member, fluid filling said chambers and said passage and which resists reciprocation of said reciprocative member, engine driven means for rotating one of said axle driving members, and means for supplying fluid to one of said chambers.

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